sealing device

Abstract

The present invention provides a sealing device that can suppress damage to a workpiece during heat sealing by precisely controlling the heater temperature. [Solution] The sealing device includes a heating unit 10 that heats the surface of the processed paper W as it is fed in the feeding direction while pressing it, and is a device for sealing the layers of the processed paper W. The first heating unit 10F includes a base 11 having a through hole 11a provided in the processing area of ​​the processed paper W, a heater 13 which is laminated on the processed paper W side of the base 11 and provided in an area corresponding to the processing area of ​​the processed paper W, with a part of the back surface, which is the side opposite to the side to be processed, exposed to the through hole 11a, and is a thin conductor that generates heat when an electric current flows through it, and a temperature sensor 15 which detects the temperature of the back surface of the heater 13 exposed to the through hole 11a of the base 11 in a non-contact manner, and a control unit which controls the temperature of the heater 13 based on the output of the heater temperature detection unit.

Description

Technical Field

[0001] The present invention relates to a sealing device for heat-sealing a workpiece.

Background Art

[0002] Conventionally, there has been a sealing device for manufacturing an air cushion material or the like by heat-sealing overlapping films while moving them in the feeding direction (for example, Patent Document 1). When such a sealing device heat-seals a workpiece, in order to suppress damage to the workpiece, it is required to accurately adjust the heater so as not to overheat the workpiece. However, the conventional sealing device did not have a configuration for accurately detecting the temperature of the heater. For this reason, the conventional sealing device had a problem that when heat-sealing a workpiece, the workpiece was overheated and damaged.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a sealing device capable of suppressing damage to a workpiece when heat-sealing the workpiece by controlling the temperature of a heater with high precision.

Means for Solving the Problems

[0005] One embodiment of the present invention is a sealing device for sealing the interlayers of a workpiece, which includes a heating unit that heats the surface of the workpiece while pressing it as it is fed in the feeding direction, the heating unit comprising: a base having a hole provided in the processing area of ​​the workpiece; a heater laminated on the workpiece side of the base and provided in a range corresponding to the processing area of ​​the workpiece, with a part of its back surface, which is the side opposite to the workpiece side, exposed in the hole; a heater temperature detection unit that non-contactually detects the temperature of the back surface of the heater exposed in the hole of the base, The sealing device includes a control unit that controls the temperature of the heater by controlling the power supplied to the heater based on the output of the heater temperature detection unit. [Brief explanation of the drawing]

[0006] [Figure 1] This is a view of the sealing device 1 of the embodiment, seen from above Z2. [Figure 2] This is a perspective view illustrating the processed paper W before sealing and the cushioning material W10 after sealing in the embodiment. [Figure 3] This is a view of the sealing device 1 of the embodiment as seen from the front Y1. [Figure 4] These are vertical cross-sectional views of the heating unit 10 (section 4A-4A in Figure 3) and the air nozzle 6 (section 4B-4B in Figure 3) in the state of processing the processed paper W of the embodiment. [Figure 5] This is a perspective view of the heating unit 10 and air nozzle 6 of the embodiment. [Figure 6] This is a cross-sectional view (6-6 cross-sectional view in Figure 3) of the heating section 10 in the state of processing the processed paper W of the embodiment. [Modes for carrying out the invention]

[0007] (Embodiment) Embodiments of the present invention will be described below with reference to the drawings and other documents. Figure 1 is a view of the sealing device 1 of the embodiment, seen from above Z2. Figure 2 is a perspective view illustrating the processed paper W before sealing and the cushioning material W10 after sealing in the embodiment. Figure 3 is a view of the sealing device 1 of the embodiment as seen from the front Y1. Figure 4 shows a longitudinal cross-sectional view of the heating unit 10 (cross-sectional view 4A-4A in Figure 3) and a longitudinal cross-sectional view of the air nozzle 6 (cross-sectional view 4B-4B in Figure 3) in the state in which the processed paper W of the embodiment is being processed. Figure 5 is a perspective view of the heating unit 10 and air nozzle 6 of the embodiment. Figure 6 is a cross-sectional view (6-6 cross-section in Figure 3) of the heating section 10 in the state of processing the processed paper W of the embodiment. In the embodiments, the XYZ Cartesian coordinate system will be used as appropriate for explanation. This coordinate system represents the left-right direction X (left side X1, right side X2), the front-back direction Y (front side Y1, rear side Y2), and the vertical direction Z (bottom side Z1, top side Z2) of the sealing device 1, as shown in Figure 1, etc. The thickness of each component has been exaggerated as appropriate in the illustration. Within the installation range of the heating unit 10 and the air nozzle 6, the left-right direction X is the feeding direction of the processed paper W (workpiece) (downstream is the left side X1, upstream is the right side X2), and the front-back direction Y is the thickness direction of the processed paper W. Furthermore, in each figure, in order to clearly show the configuration of the sealing device 1, parts of the sealing device 1 that are hidden by the processed paper W are shown with solid lines as appropriate.

[0008] As shown in Figure 1, the sealing device 1 is equipped with a heating unit 10 that presses the surface of the processed paper W (workpiece) as it is fed in the feeding direction, and is a device that seals the lower interlayers of the processed paper W (see the lower sealing range W6 in Figures 2(B), 6, etc.). The size of the sealing device 1 is, for example, portable and tabletop-sized, but is not limited to this, and may be a stationary type, for example.

[0009] As shown in Figure 2, the cushioning material W10 is manufactured by injecting air into processed paper W and sealing it, as will be described later. As shown in Figure 2(A), the processed paper W consists of individual bags W1 that are continuous in the feeding direction. Adjacent individual bags W1 are connected by perforations W2. Each individual bag W1 is made by laminating two sheets of paper. The two sheets of paper have a heat-sealing agent (for example, an olefin-based coating agent) applied to their opposing surfaces. As shown by the dotted lines and dot hatching, the individual bag W1 has a U-shaped section W5 (left, right, and top) that is open at the bottom and is heat-sealed. Therefore, the individual bag W1 is bag-shaped with an open bottom. As shown in Figure 2(B), the cushioning material W10 consists of individual cushioning material W11 that are continuous in the feeding direction. Adjacent individual cushioning material W11 are connected by perforations W2. The individual cushioning material W11 is formed into a sealed bag shape by heat-sealing the lower band-shaped lower sealing area W6 while air is sealed inside. The cushioning material W10 can be divided into appropriate sizes at the perforations W2 according to the size of the object to be cushioned, the size of the packaging box in which the object is packed, etc.

[0010] The sealing device 1 manufactures the cushioning material W10 by sequentially heat-sealing the lower part of the individual bag W1 while it is filled with air. As shown in Figures 1 and 3, the sealing device 1 comprises a base 2, a delivery roller 3, a guide 4, a feed roller 5, an air nozzle 6, a heating unit 10, and a control unit 20. Base 2 is the base on which each component of the sealing device 1 is mounted. Base 2 can be made of a metal plate or the like. The feed roller 3 is the roller on which the unprocessed paper W is wound and which feeds out the processed paper W. The feed roller 3 is located at the upstream end in the feeding direction. Guide 4 guides the processed paper W, which is fed out from the feed roller 3, toward the air nozzle 6. Guide 4 can be a rotatable roller, a cylindrical shaft, or the like. The feed roller 5 is provided on the most downstream side in the feed direction. The feed roller 5 includes two rollers 5a that are rotationally driven by a driving device (not shown) such as a motor. The two rollers 5a rotate while sandwiching the processed paper W in the front-rear direction Y, thereby feeding the processed paper W in the feed direction. The two rollers 5a sandwich the portion of the processed paper W that is heat-sealed by the heating unit 10 and the portion below Z1 thereof. Thereby, the feed roller 5 can feed the processed paper W in the feed direction without crushing the portion of the processed paper W that is inflated with air.

[0011] The air nozzle 6 and the heating unit 10 are arranged in this order from the right side X2 to the left side X1 between the guide 4 and the feed roller 5. As shown in FIG. 4(B) and the like, the air nozzle 6 injects the air supplied from an air supply source (not shown) such as a compressor from the hole portion 6a, thereby introducing air into the lower opening of the single bag body W1. The single bag body W1 becomes inflated by introducing air from the lower opening. The heating unit 10 is a device that seals air inside the single bag body W1 by heat-sealing the lower part of the single bag body W1. Details of the heating unit 10 will be described later.

[0012] The control unit 20 is a unit that executes various controls of the sealing device 1. Although detailed description is omitted, the control unit 20 includes electrical components, drive circuits, etc. for controlling the heating unit 10, the feed roller 5, etc. and supplying power to these devices, and also includes an operating device for making various settings, a display device for displaying various information (detection temperature of the temperature sensor 15, etc.). The control unit 20 includes a storage unit 21 and a control unit 22.

[0013] The storage unit 21 is a storage device such as a hard disk or a semiconductor memory element for storing programs, information, etc. necessary for the operation of the sealing device 1. The control unit 22 is a device that performs arithmetic processing necessary for the operation of the sealing device 1 and comprehensively controls the sealing device 1. The control unit 22 is composed of, for example, a CPU (Central Processing Unit) or the like. The control unit 22 realizes various functions of the embodiment by appropriately reading and executing various programs stored in the storage unit 21. The control unit 22 executes, for example, control of the feeding speed of the feeding roller 5, temperature control of the heater 13 (described later), etc. The control unit 22 can control the temperature of the heater 13 by controlling the electricity (at least one of voltage and power) output to the heater 13, that is, the power supplied to the heater 13. As an example, the control unit 22 executes the control of the power supplied to the heater 13 by feedback control or PWM control based on the output of the temperature sensor 15.

[0014] In the embodiment, the computer refers to an electronic computer equipped with a storage device, a control device, an arithmetic device, etc. The sealing device 1 includes a storage unit 21, a control unit 22, etc., and is included in the concept of a computer. Also, the computer is not limited to a form composed of a single electronic computer, and may be composed of a plurality of electronic computers as needed.

[0015] The configuration of the heating unit 10 will be described in detail. [[ID=!]] As shown in FIGS. 4 to 6, the heating unit 10 includes a first heating unit 10F and a second heating unit 10B. The first heating unit 10F and the second heating unit 10B are arranged to face each other with the processed paper W sandwiched therebetween in the front-rear direction Y. The first heating unit 10F is arranged on the front side Y1, and the second heating unit 10B is arranged on the rear side Y2. <000010!>The first heating unit 10F includes a base 11 (first base), a heat insulating layer 12, a heater 13 (first heater), an outer coating layer 14 (low friction layer, insulating layer), and a temperature sensor 15 (heater temperature detection unit).

[0016] The base portion 11 is the base of the heating portion 10. The base portion 11 can be manufactured by machining a material with a small heat capacity (for example, a resin block such as polyacetal). The base portion 11 is fixed to the base 2 by screws or the like. Note that screws and the like are not shown in drawings other than Figures 1 and 3. The base portion 11 has an elongated rectangular parallelepiped shape in the left-right direction X. When the base portion 11 is viewed from above Z2, both sides in the left-right direction X are semicircular to allow the processed paper W to enter and exit smoothly. In addition, the rear side Y2 of the base portion 11 is flat so that the processed paper W can be pressed down with a surface. In the vertical direction Z, the installation range of the base 11 corresponds to the lower sealing range W6 of the processed paper W, and the height of the base 11 is sufficiently low so as not to crush the processed paper W into which air has been introduced.

[0017] The base portion 11 is provided with a through hole 11a. The through-hole 11a penetrates the base 11 in the front-to-back direction Y. When the base 11 is viewed from the front-to-back direction Y, the through-hole 11a is located in the center of the base 11 and overlaps with the lower sealing area W6 of the processed paper W. A temperature sensor 15 is housed in the through-hole 11a.

[0018] As shown in Figure 6, the insulation layer 12, heater 13, and outer covering layer 14 are laminated on the side surface of the base 11. The insulation layer 12 is laminated closest to the base 11, and the outer covering layer 14 is laminated as the top layer, which is on the outermost side (processed paper W side). The heat insulating layer 12 is provided to reduce the amount of heat transferred from the heater 13 to the base 11. This allows the heat insulating layer 12 to suppress damage to the base 11 due to overheating. The heat insulating layer 12 can be made of a tape made of resin or the like. The heat insulating layer 12 is wrapped around the side of the base 11 so that the heater 13 and the base 11 do not come into contact. The rear portion Y2 of the heat insulating layer 12 is provided with a through hole 12a that communicates with the through hole 11a of the base portion 11. Therefore, when the base portion 11 is observed from the front Y1, the back surface of the heater 13 (the side opposite to the workpiece side) is exposed within the through holes 11a and 12a.

[0019] The heater 13 is, for example, a thin conductor (such as a nichrome foil metal plate) with a thickness of about 30 μm and an outer diameter of about 10 mm x 100 mm. The heater 13 is attached to the base 11 by being wound on the heat insulating layer 12. Although not shown in the diagram, the heater 13 is fixed to the base 11 by screwing its end to the base 11. Electrical cables 13a are connected to both ends of the heater 13, and the heater 13 generates heat when electricity is supplied from these electrical cables 13a, that is, when voltage is applied and a direct current flows. With the above configuration, the heater 13 is laminated on the processed paper W side of the base 11 and is provided in a range corresponding to the lower sealing range W6 of the processed paper W.

[0020] The temperature sensor 15 non-contactually detects the temperature of the back surface of the heater 13, which is exposed to the through holes 11a and 12a of the base 11 and the heat insulating layer 12. In this embodiment, the temperature sensor 15 is, as an example, a radiant temperature sensor (thermopile) that detects the temperature by detecting infrared radiation emitted by the heater 13. The temperature sensor 15 is inserted into the through hole 11a of the base 11 from the front Y1 to the rear Y2, and the tip of the temperature sensor 15 (the part where the thermopile is provided) is positioned to be spaced apart from the rear surface of the heater 13. The temperature sensor 15 may be held in place by press-fitting it into the through hole 11a of the base 11 using, for example, rubber or sponge. As a result, the temperature sensor 15 can detect the temperature of the back surface (front surface Y1) of the plate portion at the rear Y2 of the heater 13. The temperature sensor 15 and the control unit 20 are connected by an electrical cable 15a that outputs the detection signal from the temperature sensor 15.

[0021] The outer layer 14 insulates the two heaters 13, which are positioned opposite each other, from direct contact (as described later), and also reduces frictional resistance with the processed paper W being fed in the feeding direction, thus enabling smooth feeding of the processed paper W. For example, a low-friction fluororesin tape can be used. The outer layer 14 is laminated so as to cover the front surface of the rear surface of the base 11. Therefore, the rear surface of the heater 13 does not come into direct contact with the processed paper W.

[0022] The second heating unit 10B has a similar configuration to the first heating unit 10F, but differs from the first heating unit 10F in that it does not have a configuration related to the temperature sensor 15. In other words, the second heating section 10B comprises a base 11 (second base), a heat insulating layer 12, a heater 13 (second heater), and an outer covering layer 14, facing the base 11, heat insulating layer 12, heater 13, and outer covering layer 14 of the first heating section 10F, with the processed paper W in between. Furthermore, the second heating section 10B does not have a temperature sensor 15, and the base 11 and heat insulating layer 12 of the second heating section 10B do not have through holes 11a and 12a.

[0023] Here, current flows through the two heaters 13 of the first heating section 10F and the second heating section 10B. Therefore, if the two heaters 13 were to come into direct contact with holes formed in the processed paper W (for example, holes formed when the processed paper W is scorched during initial setup at the start of processing, or holes in the perforations W2), a short circuit would occur. The outer sheath layer 14 insulates the two so that they do not come into contact in this way, and also functions as an insulating material to suppress short circuits.

[0024] (Operation of sealing device 1) The operation of the sealing device 1 will be explained. Before operating the sealing device 1, the operator performs the initial setup of the sealing device 1. In the initial settings, the operator sets the feed speed of the processed paper W, the temperature of the heater 13, etc., while referring to the operation unit, display unit (not shown), etc. of the sealing device 1. The control unit 22 performs rotation of the feed roller 5 and temperature control of the heater 13 according to these settings. In this embodiment, the feed speed of the processed paper W is constant, and the set temperature of the heater 13 is also constant.

[0025] The processed paper W moves in the feeding direction at a constant speed as the feed roller 5 rotates. The air nozzle 6 injects air upward towards Z2 while the processed paper W is moving in the feeding direction, thereby introducing air into the lower opening of the individual bag W1 and inflating the individual bag W1. When the single bag W1 reaches the heating section 10 downstream of the air nozzle 6, it is sandwiched between the two outer layers 14 of the first heating section 10F and the second heating section 10B, and moves while being pressed. The heat from the two heaters 13 is transferred to the lower sealing area W6 of the two sheets of paper in the single bag W1. As a result, the two sheets of paper in the single bag W1 are heat-sealed and joined at the lower sealing area W6. In this way, the heating unit 10 heat-seals the inflated individual bag W1 while the individual bag W1 is moving, thereby sealing air inside the individual bag W1. As a result, the processed paper W has air sealed inside, and when it is located to the left X1 (downstream side) of the heating unit 10, it is processed into a cushioning material W10.

[0026] The temperature control of the heating unit 10 will be explained in detail. The temperature sensor 15 detects the temperature on the back surface of the heater 13 of the first heating unit 10F and outputs it to the control unit 22. Based on the output of the temperature sensor 15, the control unit 22 controls the electricity output to the heater 13 so that the temperature of the heater 13 reaches the set temperature. In this case, since the temperature sensor 15 is not in contact with the heater 13, the temperature of the heater 13 can be detected accurately and with high responsiveness. Unlike the embodiment, if a contact-type temperature sensor such as a thermistor or thermocouple is used, the large heat capacity of the probe itself affects the temperature of the heater 13, and it takes a certain amount of time for the probe temperature to reach the temperature of the heater 13, resulting in poor responsiveness. This effect becomes greater the smaller the heat capacity of the metal plate used as the heater 13.

[0027] Furthermore, since the heater 13 in this embodiment is a metal plate with a small heat capacity, the temperature detected by the temperature sensor 15 and the temperature of the processed paper W are approximately equal. Therefore, the temperature sensor 15 can detect a temperature equivalent to that of the processed paper W by detecting the temperature of the back surface of the heater 13. This makes it possible to directly set a temperature suitable for heat sealing when setting the temperature, and also to set a temperature that does not cause the processed paper W to burn. Furthermore, since the heater 13 is a metal plate with a small heat capacity, the control unit 22 can control the temperature of the heater 13 with high responsiveness, and as mentioned above, the temperature sensor 15 does not use a probe or the like with a large heat capacity, so it does not affect the responsiveness of the temperature control.

[0028] As described above, the sealing device 1 can detect the temperature of the heater 13 with high responsiveness and can also control the temperature of the heater 13 with high responsiveness. As a result, the sealing device 1 can heat-seal the processed paper W while suppressing damage such as scorching.

[0029] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above. Various modifications and changes are possible, such as the modified forms described later, and these are also within the technical scope of the present invention. Furthermore, the effects described in the embodiments are merely a list of the most preferred effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments. Note that the configurations of the embodiments described above and the modified forms described later can be used in part or in combination as appropriate, but a detailed explanation is omitted.

[0030] (Transformed form) (1) In the embodiment, an example was shown in which two heaters sandwich the processed paper and heat the processed paper from both sides, but the invention is not limited to this. For example, if the processed paper can be sealed by heating it from only one side, the heating unit only needs to have one heater. In other words, the heating unit may consist only of a first heating unit and not a second heating unit. In this case, instead of a second heating unit, a receiving unit may be provided as a member that sandwiches the processed paper between the first heating unit and the receiving unit, with the heater removed from the configuration of the second heating unit.

[0031] (2) In the embodiment, an example was shown in which both the first heating section and the second heating section are provided with an outer covering layer, but the embodiment is not limited thereto. If one of the first heating section or the second heating section is provided with an outer covering layer, short circuits between the heater of the first heating section and the heater of the second heating section can be suppressed. In this embodiment, the heater and the workpiece are in direct contact with the other of the first heating section and the second heating section. For this reason, this embodiment is suitable when the frictional resistance between the heater and the workpiece is small.

[0032] (3) In the embodiment, the sealing device is shown to continuously seal a strip-shaped area of ​​the workpiece, but it is not limited to this. For example, the sealing device may intermittently seal a strip-shaped area of ​​the workpiece (in a form in which the sealed and unsealed areas of the strip-shaped area are continuous with the feeding method). In this case, the control unit only needs to control the heater to a high temperature state and a low temperature state. Since the sealing device can detect and control the heater temperature with high response, it can control the heater to a high temperature state and a low temperature state with high response and accuracy. In this case, the control unit may make the feed speed of the feed roller variable rather than constant. For example, the control unit may set the speed at which the unsealed portion moves on the heater to be faster than the speed at which the sealed portion moves on the heater. This allows the sealing device to process the material without heat-sealing the unsealed portion even when the heater temperature has not cooled sufficiently. This allows the sealing device to seal only the necessary portion of the strip-shaped area of ​​the workpiece.

[0033] (4) In the embodiment, the workpiece is shown as paper, but it is not limited to this. The workpiece can be any material that can be joined by heat sealing (for example, a resin such as polyethylene or polyvinyl chloride). In this case, the sealing device may be used to manufacture confectionery bags or the like. Furthermore, the components produced by the sealing device are not limited to sealed bags. The components produced by the sealing device may be, for example, flat sheets. In this case, the sealing device may, for example, seal the workpiece without sealing it, or it may seal the entire surface between the layers of the workpiece.

[0034] (5) In the embodiment, the hole in the base is shown as a through hole, but is not limited to this. The hole in the base can be any shape that allows the temperature sensor to detect the back surface of the heater, for example, a notched hole. (6) In the embodiments, an example has been shown in which an insulating layer is provided between the base and the heater, but the invention is not limited thereto. If the base has sufficient heat resistance, an insulating layer is not necessary. [Explanation of symbols]

[0035] 1: Sealing device 10: Heating section 10F: 1st heating section 10B: 2nd heating section 11: Base 11a: Through hole 12a: Through hole 13: Heater 14: Outer layer 15: Temperature sensor 20: Control Unit 22: Control Unit W: Processed paper W10: Cushioning material W6: Lower sealing range

Claims

1. A sealing device comprising a heating section that heats the surface of a workpiece while pressing it as it is fed in the feeding direction, and which seals the interlayers of the workpiece, The heating section is A base having a hole provided in the machining area of ​​the workpiece, A heater is laminated on the workpiece side of the base, with a portion of the back surface, which is the side opposite to the workpiece, exposed in the hole, and is a thin conductor that generates heat when current flows through it. The base comprises a heater temperature detection unit that detects the temperature of the back surface of the heater exposed in the hole of the base without contact, A control unit controls the heater temperature by controlling the power supplied to the heater based on the output of the heater temperature detection unit. A sealing device equipped with the following features.

2. The heating section comprises a first heating section and a second heating section arranged opposite the first heating section with the workpiece in between. The first heating unit comprises a first base which is the base, a first heater which is the heater, and a heater temperature detection unit. The aforementioned second heating section is A second base portion provided within the processing range of the workpiece, The second base is laminated on the workpiece side and comprises a second heater, which is a thin conductor and generates heat when an electric current flows through it. The first heater comprises an insulating layer laminated on at least one of the workpiece-side surfaces of the first heater and the workpiece-side surfaces of the second heater. The sealing device according to feature 1.

3. The base is laminated on the uppermost layer on the workpiece side and includes a low-friction layer that reduces frictional resistance with the workpiece. The sealing device according to feature 1 or 2.

4. The control unit heat-seals the workpiece so that it has sealed and unsealed areas in a strip-shaped area along the feed direction by controlling the heater to a high-temperature state and a low-temperature state. The sealing device according to feature 1 or 2.

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